package cn.pengge.springaop.reflection;

import java.lang.annotation.*;
import java.lang.reflect.Field;

//练习反射操作的注解
public class Test12 {


    public static void main(String[] args) throws ClassNotFoundException, NoSuchFieldException {


        Class c1 = Class.forName("cn.pengge.springaop.reflection.Student2");

        //通过反射获取所有注解
        Annotation[] annotations = c1.getAnnotations();
        for (Annotation annotation : annotations) {
            System.out.println("annotation = " + annotation);
        }

        //获得注解的value值
        TablePeng tablePeng =(TablePeng)c1.getAnnotation(TablePeng.class);

        String value = tablePeng.value();
        System.out.println("value = " + value);

        //获得类指定的注解
        Field name = c1.getDeclaredField("name");

        FieldPeng annotation = name.getAnnotation(FieldPeng.class);

        System.out.println("annotation.columnName() = " + annotation.columnName());
        System.out.println("annotation.columnName() = " + annotation.type());
        System.out.println("annotation.columnName() = " + annotation.length());


    }


}


@TablePeng("db_student")
class Student2 {

    @FieldPeng(columnName = "db_id", type = "int", length = 10)
    private int id;

    @FieldPeng(columnName = "db_age", type = "int", length = 10)
    private int age;

    @FieldPeng(columnName = "db_name", type = "varchar", length = 10)
    private String name;


    private Student2() {

    }

    public Student2(int id, int age, String name) {
        this.id = id;
        this.age = age;
        this.name = name;
    }

    @Override
    public String toString() {
        return "Student2{" +
                "id=" + id +
                ", age=" + age +
                ", name='" + name + '\'' +
                '}';
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

//类名的注解
@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@interface TablePeng {
    String value();
}


//属性的注解
@Target({ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
@interface FieldPeng {

    String columnName();

    String type();

    int length();

}